Reasons for Halo 5 selling less:

1. Scores aren't so good. If it would have a meta like the other main Halo games it would have sold better. Just imagine a Meta of 93 or something instead of 84^^ this is a big factor especially for people who don't have much money to buy many games. 

2. Many fans were just not happy about Halo 4 and Reach and lost interest in the franchise (which may come back with the multiplayer now, maybe they just didn't buy it at release because of how Halo 4 multiplayer was)

3. No BTB, no splitscreen, no forge at release, this is all stuff some Halo fans bought Halo for. Especially splitscreen is a huge thing for many Halo players so that some will never buy Halo 5 now. 

4. Two other huge futuristic shooters releasing straight after it. Some not so huge Halo fans did probably think they will buy Battlefront or Black Ops instead. If there would be no crazy Star Wars hype this year and if it wouldn't be Black Ops but another CoD (Black Ops seems to be the most beloved by CoD players) sales could be also higher.

5. MS said it's the best line-up Xbox ever had, this may be true for many but this also means people have simply more choices this winter.

6. People want the Master Chief and this always and not only in parts of a Halo game. For many, Master Chief is Halo, as simple as that.

7. The MCC was a mess for many, I'm not surprised that there are people who didn't want to buy Halo 5 at release havig this in mind. Yes, we hardcore gamers know that one had nothing to do with the other but what's with casual gamers? How does average Joe who had a mess with MCC think about the Halo 5 release? He may be scared that his game won't be really working. 

I didn't know that 935 k got confirmed. Let's say it is true. Npd ended on a Saturday, so we will call it 1 million fw. 150k in uk. U really think only 150k rest of the world. I think it's more like 350k. So that's 1.5 million fw retail.  if digital is 15% fw sales are 1.725m. If digital is 25% it's 1.875, and if 35% 2.025m. I could have been low balling rest of the world as halo generally does 60% of fw sales in America. If I was off each one of those numbers is a hair over 100k low.

The Xbox Black Friday sale is going to hurt my wallet. Quite excited to see what games will be there.

People, i have a question to all of you, about two RPG'S;
Dragon Age Inquisition and The Witcher 3 Wild Hunt.
Wich of this games have the most difficult bosses to defeat? How much time to make 100% they take?

About the Xbox sales, i don't have any concerns, because i know that Microsoft will not let the Xbox brand go.
And in the long run, the sales will be good. We all Xbox gamers will have a amazing 2016 with plenty of games.

BTB is ready in Halo 5 now.

Can only answer for Dragon Age Inquisition.
100% can be achieved in 82 hours (that's the time it took me to get all of the achievements on normal difficulty)
DLCs will add about 25 hours.

Boss fights aren't particularly hard except for the optional dragon fights.

Bought the retail version of Shadow of Mordor GOTY Edition for 23€.

I hope I don't regret it when the Black Friday deals hit, but this deal was too good not to buy.

Xbox is pushing BF digitally starting the 20th(early access) whatever that means. I saw Gears, Witcher i think Forza 6(yes) and a few others. Hopefully they match some stores because i don't want physical anymore.